A known form of driving belt comprises an endless flexible metal carrier on which is mounted a plurality of plate-like elements disposed transverse to the carrier and in face-to-face contact with each other. The carrier is formed of one or more band packages each of which includes a plurality of endless bands arranged in overlying concentric relationship, i.e. arranged radially around each other. Belts of this kind are disclosed in U.S. Pat. Nos. 3,720,113 and 4,080,841.
Belts of this kind have utility in variable ratio transmissions in which the belt runs over pulleys constructed of conical discs which are adapted to be displaced axially relative to each other so that the running diameter of the driving belt over the pulleys may vary. In practice, such a driving belt is under high tension in order to ensure a proper frictional contact between the pulleys and the transverse belt elements, and to properly conduct the transverse elements in the straight part of the belt.
The efficiency of such a driving belt is rather high, but there remain internal losses in the belt as a result of frictional forces between the various parts.